I 

 508 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



COMANTHERIA INTERMEDIA A. H. Clark 



Plate 60, Figure 169; Plate 61, Figures 171, 172; Plate 65, Figure 182 



Comantheria intermedia A. H. CLARK, Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 214 

 (nomen nudum; southern Japanese species; range and its significance); Proc. Biol. Soc. 

 Washington, vol. 29, 1916, p. 105 (description; Sagami Bay, Japan, to about 150 m.; rela- 

 tiDnships); Unstalked Crinoids of the Siboga Exped., 1918, p. IX (relationship with C. weberi 

 and C. rotula); p. 43 (in key; range). 



Diagnostic features. The centrodorsal is thick discoidal and bears numerous 

 cirri, of which only a few are well developed. These are slender, but long, usually 

 between 23 and 25 mm. in length, and are composed of 20-28 (usually 24-26) seg- 

 ments. There are 31-48 (probably most commonly about 40) arms. 



Description. The centrodorsal is thick discoidal, from 7 to 9 mm. in basal 

 diameter and from 4 to 6 mm. across the concave dorsal pole. The cirrus sockets are 

 arranged in two and a partial third crowded alternating rows. 



Usually there are only a few well-developed cirri, the majority being more or less 

 rudimentary. They reach a maximum of XXXII; they have 20-28 (usually 24-26) 

 segments, and are from 18 to 30 mm. (usually between 23 and 25 mm.) in length. 

 The longest segments, in the proximal portion, are about one- third again as long as 

 broad, and the distal segments, from about the eleventh onward, are about twice as 

 broad as long; the transition from the one type to the other is rather abrupt. The 

 short distal segments have the dorsal profile convex, the maximum height of this 

 convexity being at first at the distal end of the segment but gradually moving proxi- 

 mally, so that the distal segments are provided with low blunt median tubercles. 

 The opposing spine is transversely elongate. In general the cirri resemble those of 

 C. weberi, but they are much more slender, much less curved distally, and are com- 

 posed of a larger number of segments ; the relative number of more or less rudimentary 

 cirri is greater in this species than in C. weberi. 



The arms are 31-48 (averaging 40) in number, from 130 to 180 mm. (averaging 

 about 145 mm.) in length. The division series and brachials resemble exactly those 

 of C. weberi. 



Notes. Of the 3 specimens from between Ito and Hatsushima Island the most 

 developed has 48 arms. Two of the IIBr series are 2, the remaining 8 being 4 (3+4). 

 Eighteen of the IIIBr series are 2, and 2 are 4 (3 + 4). The IVBr series are 4 (3 + 4), 

 but are 2 if they follow IIIBr 4 (3+4) series. There are no fully developed cirri. The 

 division series are comparatively broad and stout, approaching the conditions seen in 

 Comanthus solaster. 



The second specimen has 35 arms 140 mm. in length. One of the IIBr series is 2, 

 the remaining 7 being 4 (3 + 4). Fourteen of the IIIBr series are 2, and 2 are 4 (3 + 4). 

 The single IVBr series is 4 (3 + 4). The centrodorsal is 9 mm. in basal diameter, with 

 a concave dorsal pole 6 mm. in diameter. Only one of the cirri is fully developed. 



The third specimen has 31 arms 140 mm. long. One of the IIBr series is absent. 

 The 9 present are all 4 (3 + 4). Ten of the IIIBr series are 2, and 2 are 4 (3 + 4). 

 The division series are broad and nearly in lateral apposition, but are well rounded 

 dorsally. The brachials are rather strongly overlapping. The centrodorsal is 7 mm. 

 in basal diameter, thick discoidal, with a broad and slightly concave polar area 5 mm. 



